Multiple Rapid Charging / Charging concerns & why I wouldn't buy a 39kWh Kona Electric

[@apsolltd]

Hi Nigel, rapid charging of a cold battery will be severely limited. In my Tesla 90D on a cold morning I can only get 29kW rather than 94kW until the battery is thoroughly warmed up. Regen braking is reduced for the same reason. David

[@EVPuzzle]

Cheers David. Its all understandable I guess just a shame manufacturers can't be more open about charging limitations

[@BSAT10]

Hi Nigel I haven't done multiple charges on my 40KW leaf but on a normal fast charge it does about 43KW while below 50% state of charge and after that it starts to vary As a rule of thumb if you took the state of charge% number and add it to the KW/h charge rate they will total 100 So at 60% charged you will be getting 40KW/h -- (add together 60+40 =100) and at 70% charged it will be getting around 30KW/h at 80% charged you get around 20KW/h at 90% around 10KW/h You get the picture. So you would need the patience of a saint to get to 100% on the rapid charger I always push off somewhere North of 80% :)

[@markjennings2315]

If a 39Kwh capacity battery is charged at the same rate as a 64Kwh capacity battery, it will be being charged at nearly twice the energy/battery cell as the larger battery. This is why the 39KWh battery will have lower KWh charge rates. When the 39Kwh battery is charging at 46KWh that's 1.1xC/Kwh. When the 64Kwh battery is charging at 46KWh that's only 0.7xC/Kwh. (C is the batteries Capacity) As both size batteries have the same 54 mins charge to 80% figure then the Charge rate for the smaller battery has to be less than that for the larger. I think the slower rates are the BMS doing its job and protecting the battery cells from charging too fast. I wonder if this demo cars battery has ever been charge to 100 percent (and given time balance cell voltages)

[@claytonroot806]

I'd say this is the first explanation that makes sense and thus makes purchasing the largest battery you can afford, that is if picking up miles of range per hour of charging is a concern. It may also help explain why Tesla's batteries (all of them are larger capacity) seem to have slower rates of degradation than those in other cars with smaller batteries. Each individual cell is not getting hammered so hard or as frequently over the same distance traveled.

[@EVPuzzle]

It was at 100% when it arrived and yes what I saw is the car protecting the battery from cold , which increases charge time beyond what Hyundai state

[@williamcox1176]

Just a thought, And you covered most of it, Having the bigger battery and better efficiency, The 64kwh Kona's battery per cell is doing about half the work (charge/discharge) as the Nissan leaf, and with the water-cooled battery management should degrade at half the speed.

[@EVPuzzle]

I think the Kona is dissipating heat better enroute

[@rossmc40]

@@williamcox1176 from some videos Euan McTurk has done it's not quite that straightforward. The smaller battery cars will cycle more often but each cycle will transfer less power so causes less degradation with each charge. Over the lifetime of the battery I imagine more capacity will help with lower degradation but if you look at 22kw Zoe's their SOH even after 50k milesis still in the high 90's What will give it an advantage over the Leaf specifically though is the liquid cooling. Temperature seems to be the real killer of li ion batteries now that BMS prevents high/low SOC problems.

[@markleon411]

This is very good to know. Thanks for delving into this. I am planning to buy a Kona Electric when they are released in Australia later this year and was wondering about which one to buy.

[@tomooo2637]

As a ball park : Batteries for cars are constructed in banks, and in each bank the cells have a standard in-series and in-parallel set of single batteries. For a particular make of battery then each bank of battery can be charged at a maximum rate. A small battery (39kW) will have a number of banks - lets say 4. A large battery (64kW) will have more banks - lets say 7. (yes those number don't work, but hopefully you get the idea.) The motors used are designed to be used at particular voltage, so a large battery has the banks in parallel - so you get more current - but no more voltage. Since the larger battery has more banks in parallel - you can change it faster, and you can get more amps out of it (power). The smaller battery car will charge slower, and have less acceleration. The larger battery can be charge faster and the car can be make to accelerate faster. The two cars can be charge in the same time (approx)- since the larger battery can be charged faster - more amps - since the banks are in parallel, and the charge rate for each bank is the same. Batteries really don't like to be discharged and they don't like be over charged, and for those in cars the battery management will attempt to protect the batteries 1) It will warn you when you get low in charge, and reduce power at very lower power and will not tell you about the reserve 2) It will only charge at full power up to 80% charge : and that depends on the charger and on the temperature of the battery 3) above 80% the battery management will reduce the charge rate - to protect the batteries, and above 90% you will get very low rates, and about 98% it will be a trickle rate - or they will fail in a bad way, and you don't want to be in the car when that happens. 4) Batteries hate the cold - and if the batteries are cold the battery management will reduce the charge rate, same with the heat (hence the charge-gate) 5) The Kona battery (large one 64kW) will charge up to about 100kW, but in the UK we have a crap changing system, so a lot of the differences will be down to the crap chargers. The kona small battery will take a smaller rate, but should go up to 50kW. I agree that the 64kW Kona is a ground breaking car and the better than the 39kW and I hope it makes Hyundai a lot of money as the other car manufactures just don't get it..... And if you are not bored yet : one final bit of technical detail Although car batteries and phone batteries are Li-ion the tech it different. In phones, the battery is designed to have a high charge-weight capacity (we like lite phones that last a long time), but the batteries won't last long 1 to 5 years depending on how you use/abuse them. Ie if you discharge and charge to 100% every day - expect 1 year, if you keep 20% to 80% you will get 5 years. The battery management is minimal - you have to do it manually. Car batteries are heavily managed (you are sitting on a lot of energy - going wrong is not an option), and use tech that is designed for long life, not for best weight. Tesla statistics have shown that their car batteries have 90% capacity or better even after 10 years and for most other companies you should expect the same lifetimes - certainly from Hyundai.

[@EVPuzzle]

If Hyundai build on their technology rather than just repeat the same thing for years they'll dominate the market BUT if they stop here, others will catch up quickly. The Ioniq needs a update for next year really so it'll be interesting to see how each model changes or not over time

[@MiguelRamos-up5tf]

So, you discovered coldgate on the Kona! Well, relative to the battery capacity, 40kW is a faster charging rate in the 39kWh than in the 64kWh. Charging batteries in cold weather can be damaging. It all makes sense, except we expected the Kona to turn on the battery heater and perform well as the Ioniq does, with an even smaller battery. Thanks for the honest videos.

[@EVPuzzle]

Yep, and not as good as a Nissan Leaf potentially too.

[@davidbarr5783]

So much for CCS. Think I'll stick with my Zoe Q90 as I got 24.8 kWh in 45 mins at Southwaite Southbound on October 16th. Admittedly, this was after driving 110 miles limiting myself to 60 mph. And there was me thinking my poor 43kw AC charging car was inferior. At 15k miles thus far I find driving it a long distance first helps that charge rate massively. Thanks for that video as it was really informative.

[@EVPuzzle]

Getting a quick splash and dash doesn't seem to work when cold so charging before you set off on a rapid charger isn't going to be quick

[@ZeroTailpipe]

I think you’re right here that not knowing fully what the car is doing and not knowing fully what the charger is doing is unhelpful. I recently got 46kW at high 60% SOC on our IONIQ then 30-ish at 40% on the same charger a day later. Lots of variables and not a very transparent end user experience for us, all in all, as you say :)

[@andywonline]

looking forward to you doing a rapid charger tour/comparison. :)

[@EVPuzzle]

I think it's counter productive of Hyundai to hide what the car is doing and why. It would be better to be open with the end user.

[@tomeli282]

Great work you're doing look forward to every blog thanks. I'm getting a better understanding of owing and running an EV now and that on average that the Kona will travel 4 miles per one kilowatt of storage so the range is approx 4 X 64 = 256 miles. So another consideration has become evident ( for the potential buyers) using the Kona as a bench mark if I may, say the cost to purchase is approx £30000 for the 64kwh divided by the range then that figure works out to be £117 per mile, so that's the purchase price bench mark I'm using here, now compare that against say the Jaguar Ipace of £64000 and a range of 234 miles then the figure is £274 per mile. Think you got a great car and deal there and will now be judging future EV car prices on this formula as a basic guide as value for money.

[@robsmith1a]

The first thing that you've said where my Zoe has an advantage is that the heater is pretty good in the Zoe. The fans are really loud in the Zoe too, louder than the engine in a modern petrol at tick over I'd say. The Zoe pulls a consistent 22kw up to a bit over 80% then it slows a lot. I'm not sure charging speed matters so much once the range is over 300 miles because the need to fast charge will be such a rarity, you definitely have the right car with the 64 kwh model.

[@zoominbc]

As you pointed out these kinds of tests are a little tricky because of all the parameters. I wonder if the cooling fans are used to cool the bms. I thought the batteries are liquid cooled but I could be wrong though the fans may push air through a radiator. In any case something like leaf spy would give a better understanding of what’s going on.

[@EVPuzzle]

That's the point, it sounds like fans but I have no idea what it actually is. The different times it became active was confusing for sure. Nothing obvious. The difference between Nissan openly showing battery temperature and Hyundai hiding it is interesting.

[@williamcox1176]

Hi Nigel, I do like your video's, You do all the shit i'm interested in and can't be bothered to do myself. By the way, I picked up my Kona Wednesday and loving it, If I get time I will pop over to an Instavolt charger tonight and see how it does, not a great test as it will be on about 50%. With normal driving with heater, i'm getting 4.2 mpkwh, But have some long trips next week so will keep you updated if interested.

[@EVPuzzle]

Course I'm interested. Charging on the Instavolt from cold is the issue. My 64 is perfect on the Instavolts only that 39kwh version seemed a challenge

[@johnm5417]

I wouldn't get the ioniq38.3kwh it's just as bad. I'm going complain when it gets its first service, I hope that they could do something about it if they can't, I will have to avoid ev charges that charge by the minute. You would be better getting the 28kwh it charges alot quicker.

[@trevorbromley-palmer]

That noise happened to me the other day just reversing out of my garage. I had not heard it before and I thought something has gone wrong with the Kona. Glad I now know it is the BMS fans and yes they are loud.

[@EVPuzzle]

From cold Trevor?

[@trevorbromley-palmer]

The EV Puzzle yes in terms of first drive of the day. But it was in a garage so it never gets that cold.

[@EVPuzzle]

A bit like I've experienced then, absolutely no idea what it was doing or why. In my 64kwh, I haven't heard it ever. Not sure if I should be concerned mines not working or whether the 39 kwh is just normal for that battery size. If only Hyundai would make it clearer.

[@trevorbromley-palmer]

The EV Puzzle It is only the once I have heard it, and I think I got my 64kWh a few days after you. The noise actually sounds like the Kona is going to turn into a hovercraft. In my case, it didn’t stay on for long (only half a mile or so).

[@EVPuzzle]

Definitely odd that it sounds like a fan starting up but from cold you'd expect it to be warming

[@brucemcpherson8832]

In the same way that high battery temperature reduces charge rate, low battery temperature will certainly result in a low charge rate. Presumably the BMS is programmed with charging rates related to battery temperature and it acts to prevent the battery overheating, but does it have the capability to heat a cold battery so that it can handle a higher charge rate? To do that, the liquid flowing through the battery pack would need to pass through a heat exchanger, external to the battery pack, to be be either heated or cooled depending on the actual battery temperature. I had presumed the fans were simply blowing cool air over some sort of radiator that the liquid passed through, resulting in the liquid being cooled, but it may be that there is some sort of heater in the system so that the fans can blow warm air over the radiator to heat the liquid.

[@jujitsuboy730]

Bruce McPherson This is vaguely how Tesla does it. Preheat the car and in turn you warm up the battery. I start my Model 3 about 15 minutes before I set off in the morning and may have only a few dashes of limited regen on the power meter.

[@EVPuzzle]

Sounds sensible. The annoyance is not knowing. Its doing something because it's hot or cold, which is good, it's protecting the battery but it's not clear on buying the car how much temperature will or will not impact charging times. Its just fuzzy, which is my concern mostly. We need more clarity before we buy the car

[@tarassu]

BMS never switches off. Always cools and cools. Passive cooling (liquid just circulates) when very warm and active cooling (liquid is also cooled with AC compressor) when too warm. With bigger battery, charging rate (C-rate) is smaller in case of 50kW charger. So 25kWh battery charges at 2C on 50kW charger and 50kWh battery charges at 1C with 50kW charger. The slower the charge rate, the better efficiency, the less heat loss there is. Therefore less cooling needed.

[@EVPuzzle]

All good info but why does the Ioniq charge faster?

[@MikeDWinter]

Interesting experiment, Nigel. I think what you have proven is that there is no point planning a 'splash and dash' top up on a cold battery. They also can take some time to warm up to a temperature where they will charge quickly. Zoe owners with the 43kW charge option often find they need several miles at 70 mph ahead of the charger to get a decent rate. You may have seen the videos where Tesla Bjorn says you should always supercharge your Tesla the night before a journey while the battery is still warm from that day's driving, not wait until the morning, as rates will be substantially lower with a cold battery. I also wonder whether the pack voltage may have some effect on the differences you see. The 39kWh battery is 327v and 64kWh 356v. So a lower current is needed for the 64kWh pack to deliver higher charge rates. I also think that driving with a 150kW motor on the larger pack vs 100kW on the smaller may enable the larger pack to get up to temperature more quickly as you drive too, especially if you drive in a 'spirited' manner. Finally, is the larger pack liquid cooled? I wonder if that is why you get more fan noise from the smaller pack, which I understand is air cooled.

[@EVPuzzle]

Good thoughts. That's my point to the video, we just don't know until we get the car. Its all hidden until you experience it, which is surely wrong. I suspect you're right in several respects

[@MikeDWinter]

@@EVPuzzle Some manufacturers have a battery heater in their Scandinavian market models (I know Zoe does).. I recon if you'd caned the 39kWh model for a good half hour first, you probably would have seen a higher initial rate of charge. I sure that's why your final charge was at a better rate. It is good to share the information about where the step-downs occurring during rapid charging too. Again, when Bjorn tested it, I think he said there wasn't much point carrying on rapid charging after a certain SOC because you'd get a higher rate at the next charge and lose time if you stayed where you were charging. As with all new models, I guess its a bit of a learning curve and it does seem that manufacturers are really only interested in presenting the best case charging scenarios.

[@EVPuzzle]

Exactly, even though I know why I got the result I did, it's still disappointing the 39kwh isn't a step forward from the Ioniq and Leaf

[@edwyncorteen1527]

What you are seeing here is a cold battery charging issue which is expected, once you warmed it up you got normal charge rates, in a real test you would start out with 100% drive for a least 100 miles heating up the battery and only then rapid charge, does the Kona not have battery temp readout, very poor if it doesn"t.

[@therandomtester9561]

This is gonna be a long one, so bear with me Nigel.. As you probably know, I've done some testing with my -13 Leaf, had it since march -15 and drove approx 50'km now. Wanted to look into the Ø (average consumption) now. And possibly find some other answers at the same time, perhaps battery capacity and its losses.. The old Leaf can stop charging at either 80% or 100%. I tested chargingloss once in -15, charge to 80%, drive to around 3% and charge back to 80%. Numbers I collect from these early tests are: From car: SOC, Ø, km driven From Leafspy: Wh used, kWh remain, SOC. The SOC in Leafspy shows different numbers than car, fully charged is around 97.1% and empty is never tested, but around 10-12%. For charging that time, I collect numbers from my grannycable (EVI, kohns) with digital display with chargingtime, A, V, and of course kWh. In addition the chargepoint has a digital kWh display. Collected data in that trip is 110.5km, Ø12.2kWh/100km, 79% to ---% (estimated 3%), LeafspySOC 78.9% to 13.6%, 13,786 wh used, Charging 15.71 kWh on grannycable, 15.3 kWh on chargepoint. Ø*km has just 2% diviation from wh used, so fairly spot on. I end up with 9% to 16% chargingloss. I also have kWh remain on Leafspy, but there is a setting with wh/GID that may be off, so I wouldn't rely on that too much. Extrapolated I should be able to charge 20.66 kWh 0-100%, 18.6 kWh usable if we say 10% chargeloss. I believe these Leafs are suppose to have 20 kWh usable, so 18.6 I guess sounds about right. Then in -16 I did a drivestyle-test. 4 trips of 23km each, 2 with steady speed and 2 with "rollercoaster". Speeds where 30-60 km/h, average around 40 km/h. Sadly I didn't collect charged power, but all the others I've got. Rollercoaster is simulated best economy for fossil, build speed downhill, slow down going up. Every trip had of course no use of heater, same setting on everything down to volume on radio, and of course same start-turn-endpoint, and the pairs I tried as good as possible to match average speed. All numbers correspond pretty good to each other, except one: Ø! (average reported in car). All trips started with 79% charged, everything reset. Trip 1&3 are rollercoaster, 2&4 steady speed. Tripnumber 1 2 3 4 SOC end 57 63 58 67 Ø in car 14.3 13.8 13.3 13.6 wh Leafspy 4140 2925 3775 2276 Then I'll calculate the average kWh/100km based on the wh used: Ø calc 18.0 12.7 16.4 9.89 If I extrapolate the numbers to get total battery capacity, from wh used in Leafspy I get a steady 18.4 kWh. However with Ø shown in car, I get anywhere from 14.6 to 25.3 kWh. So clearly, this time the average in car is way off... And, in that test steady speed uses 30-40% less power than "rollercoaster"..!! In another test I estimated the regen to be around 90-95% efficient. The other day I drove down to ---% again, and charged up to 80%. Normally I charge to 100%, but remembering the first test I mention, it would be a good comparison. Granted, I did get a replacement EVI-cable, so it may read different numbers than the one I got that time. And the chargepoint with display is shut down. It reported 13.65 kWh (vs 15.7 kWh in same test back in -15). So about 15% less than same result 3+ years earlier. 15% degredation, 16.16 kWh available? It's possible, but really sounds like a lot of degredation... But then I just unplug, replug and charge to 100%. 79 to 100% 6.88 kWh So total 3% to 100% is 20.53 kWh. A few days later I charge 82 to 100%. That reads 4.193 kWh which does not correspond to 6.88 on 79-100%. Again a few days later, I charge 3-100% with 20.63 kWh which does correspond to the 20.53 kWh total done the week before. Also if extrapolated the 15.7 kWh 3-79% done 3 years ago, it corresponds with no degredation (actually about 2% better capacity today, but that could be down to balancing and slow chargespeed at the end). So right here I start to think that something weird happens above 80%, maby only when you've gone under 80% before charging. And, possibly, it's been a long time since I regularly charge to 80, but 3 years ago I normally did. So I am gonna do some 80%-charges in the near future to see how they correspond. Lately I've got 3 chargings up to 100, and noted Ø and km at some points along the way. Everytime I noted numbers just when it went down to the noted %. 74% could be 74.0 to 74.9, so I tried to eliminate that variable. I later found out that Ø updates as rare as every 30 second, given short trips it may give a noticable variable. But Ø is at worst within 10% diviation between the trips, so with a few variables here and there I'd say it's fairly constant this time. But, when I look at kWh charged vs Ø*km, I'm looking at around 30-35% chargingloss..!! That can't be right, right..? So what is the true consumption..? The car says 16-21 kWh/100km. Calculating 10% chargingloss from my grannycable, I'm looking at 19.4-26.1 kWh/100km. We've had around 0C here, and for the 2-6 km each trip, the heater runs hard, so I think the Ø is a bit too kind. I know preheating doesn't count on Ø, so never used it in these tests, and car is always of during charging. So it seems the more I test, the more confused I get. What numbers can you really trust? What I found to be most trustworthy is Leafspy and SOC. I also ran a "speedtest", going back and forth on a small stretch (about 2km each way) in different speeds (40-80 km/h), writing down wh from Leafspy at given points. After a few runs, I saw it was dead accurate, after the trip down, I could calculate the return within 1% or so. What gives the diviation then? The batteryheater? No, it should activate only when the batterypac is below -15C or so.. Internal resistance in battery? Sure there is some. Going to my drivestyletest, loads should be higher in the steady speed-runs because it works harder uphill, thus higher resistance. Internal resistance is not counted, so Ø should read false low. But actually it reads false high. Slow update of Ø? Probably in the latest test. But again going to the steady vs roller, drivingtime is almost the same and car never shut off during test. After 23km driving, sitting with car idling with heater off, the Ø changes maby from 13.0 to 13.1 the next update, not 15.. And why does wh used in Leafspy seem to be trustworthy, but the Ø in car not? Leafspy does get it's number from the car.. Really, I don't know.. Hope you can give some pointers,

[@EVPuzzle]

Rayner, I'm afraid that's beyond me. I do think however the GOM and battery levels in car are a digital impression of what we want to see not an accurate representation of physical states. Its software and software has bugs and coding design flaws. Leaf Spy must be more accurate as it uses the raw data and presents as is without any modification. Higher charge loss at high end of SOC definitely sounds confusing at those rates. Even balancing and conditioning of the battery can't take that much. Mystery for sure. Is it worth pursuing? Will we ever know the truth....I'm asking same question in next video

[@therandomtester9561]

​@@EVPuzzle for sure a mystery.. Yeah, I assume it will be hard to get it accurate, easier to measure 1 liter than 1kWh.. But I would at least expect the numbers to be somwhat consistent.. Well, Leafspy should use the same raw data as the car. For sure, there may be diviation, I guess I would "allow" within 10%. But I see far from that from time to time. Worth pursuing? Well, for sure the easiest is to charge whenever you need, drive whenever you want. But it would be nice to find some real answers. Also should be able to reliably charge to see battery degredation.. Hope you see more consistant numbers than I do, so it's just a Leaf-thing ;)

[@EVPuzzle]

Rayner I think you see more than Hyundai owners. My suspicion is were not seeing actual data we're seeing a slightly blurred view masked by the software, in the same way efficiency and range numbers on ICE cars seem to have a mind of their own at times. How many miles you can drive on how many kWh from the same source is all that counts to me. I need to do some benchmark tests to track usage over years to come . Problem is with 100% SOC I need to drive nearly 300 miles just for a test, then half that for 50% then half again for 25%. All with aim of repeating each year. Lots of effort but not sure how I'll know if there's degradation otherwise

[@therandomtester9561]

​@@EVPuzzle yeah, you see a lot with Leafspy, but I rearly connect it. On ICE-cars I've seen them being of by as much as 10% I believe (of course showing 10% lower consumption than in real life), but at least they seemed to be consistent.. Again, it's easier to measure 1liter than 1 kWh.. I guess I can get on to a theory why it's not correct here. Voltage fluctuates all the time, and of course fluctuates more with higher loads/regen. If the car computer is lazy, it calculates the load/regen just ever so often. And at those times i would calculate kWh based on wrong V. Leafspy might use more datapower to calculate it correct. Based on that, a drivingstyle with low inputs should give more accurat numbers than a vigurous style. My drivingstyle is "always" the same, so might explain why tests the last days shows the Ø to be pretty consistent. Oh that part is so much easier with the old Leaf, these days I struggle to squeeze 100 km from a full tank ;)

[@therandomtester9561]

Tested a little charging up to 80% now, and plotted in the numbers. You know the horrible range on my Leaf these days (around 2% pr km), so you can only imagine what it's like charging to 80% and trying to calculate running it down quite a bit before a new charge, and my chargepoint is sadly at work. But the good thing is that it only takes a few days to collect data on a number of charges ;) Anyways, when extrapolated, there is, as always.. a small diviation. I see more of a diviation charging up to 80% than to 100%, so that may be because it charges at "around" 80% while 100% is 100%. Extrapolated, charging up to 100% it seems the cable could deliver 22 kWh, while up to 80% (extrapolated to 100% capacity) it would be 18 kWh. So clearly something is happening at the end. I really don't notice that the top % are bigger, but still it could be the reason.. When comparing the cars reported Ø to the charged kWh, it seems to be fairly steady diviation of 35-40%, not included chargingloss. I guess I have to try driving with Leafspy for a comparison again later, and type2-cable at a chargepoint giving kWh-reports. I see no reason to believe that the chargingloss really is 30-40%.. Without chargingloss, my comsumption the worst days seem to be just shy of 300 wh/km. Fairly high, but compared to a diesel, that would be 3 l/100km, so still perhaps around half energyconsumption of a comparable diesel. Based on the ONE charging I recorded 3+ years ago, 50'km less, it seems like I indeed have about 13-15% degredation. It seems it charges a little faster now than before, and a "regular" drive we sometimes make without a charge during summer seemed "unpossible" this summer.

[@tonibrucker2053]

Very good video with interesting results. What’s strange: so much noise from BMS cooler for so little charging power. The 39kWh Kona seems to be less capable than the 28kWh Ioniq. That’s surprising...

[@EVPuzzle]

Toni, yes it'd be nice to know what it is and what it's doing but Hyundai in their wisdom think we don't need to know other than its managing the battery but secrecy just leads to misconceptions. It does look like the Ioniq charges better

[@colinphillipson4830]

It's my opinion that the batteries are made and supplied by two different manufacturers. The 39kWh by SK Innovations and the 64kWh by LG Chem and both having different BMS and possibly the SK Innovations BMS version may be over protective, similar to the AESC Nissan 40kWh battery even though the Kona 39kWh has active cooling? Mind you some of the loud fan cooling noises being made whilst charging are a concern and I certainly would not be happy if I had to endure that noise, especially as the 64kWh is near silent when charging. Looking forward to your 64kWh same comparison test.

[@dickmartino9933]

I think the rate of charge is normal for an electric car - slow at low SoC then faster, then slower from 80% . The estimated time on the electronic to charge may be misleading. A smaller battery or the design may not dissipate heat as well as the bigger battery in the 64kWh. I assume you were the only car using a charger i.e not sharing the stall with another car.

[@dojohansen123]

Yes. Chargers are current-limited, typically 100A or 125A for 50 kW chargers, so if the voltage is 300V, 30 kW is the maximum on the 100A charger. But the battery pack temperature also matters. And the size of the pack. And the particular chemistry. And whether the cells are balanced (all individual cells at the same SoC/voltage). And the strategy chosen when implementing the BMS. Tesla for instance seem to use a formula that continually adjusts the charging speed depending on the above variables, and potentially others, Hyundai appears to either adjust the speed much less often or choose one of a few significantly different levels. (If you make a curve showing power vs SoC (or time) it'll be fairly smooth and continous for a Tesla, but show distinct "levels" with abrupt transitions, like the diagram shown in this video, for the Hyundai. Whether Tesla or Hyundai takes best care of the battery is impossible to say based on this, but it seems logical that optimal speed varies continually, so it seems only Tesla's approach could potentially be optimal.) The point being just this: it's pretty complicated. The factor you put forward is certainly significant and relevant, but it's far from the full story.

[@enyaq_gorm]

Wow, that seems much more aggressive tapering than I see on the 40 kW leaf. Weird. Re the heating we've found the leaf is the opposite, we need to turn the heating down. Even at around zero degrees outside if we have it any higher than 17 degrees it's too hot. The leaf seems to charge at 45 kW until around 60% charge and them drops down to around 35 kW. It only drops down to the 20s when you get past 70 to 80%. Wonder what's going on.

[@EVPuzzle]

It left me wondering for sure especially when the Ioniq appears to charge quicker.

[@enyaq_gorm]

Yes very odd. But lemon tea leaf has been wondering with a few of us whether Nissan have done an over the air update because we're seeing different charging behaviour across a number of cars. They are tapering the charge more gradually, ie it isn't just blasting on 43kw until it hits a certain percentage. The tapering is more linear it seems. Not studied it but they may all be trying to work out how best to avoid cooking the battery. Certainly on this evidence it's quicker to charge a 40kw leaf than a 39 kW kona. Truly the EV Puzzle

[@EVPuzzle]

Its arbitrary I guess as the 64 doesn't have such issues it seems. Mind boggling why the 39 might be so different with the same technology

[@enyaq_gorm]

@@EVPuzzle even your expected time from 20% to 80% is slow compared with my experience in the Leaf. Not at all what I would have expected with active battery cooling / heating I did a charge from 18% to 87% the other night in 43 minutes and that's faster than even what you expected in your comments above

[@rossmc40]

@@enyaq_gorm I'll 2nd those Leaf comments. I charged from 14 - 80% in exactly 40 mins last night. This only raised my battery temp to 50% meaning if I drove at my normal 62 for 100 miles my next charge would have started at over 40kw. I can't believe Hyundai would throttle the charge that severely on a thermally managed battery. Seems like a fault. Comparing the throttling to the 64kw is a bit unfair. 80% on a bigger battery still leaves much more room so won't throttle nearly as much.

[@michaelkitchen5719]

While it may be possible to set the car up at home to be nice and cozy from the start, once at work, there are not charging options. The issue you have thrown up regarding the temperature settings are of concern. You may say, forget the dial figure and just turn it to where you are comfortable, but to have 'cold' air blowing through should only work in the summer with a temperature sensor facing the windscreen. It would appear that everybody should test their dream EV car in the winter to ensure that it will perform as they would like. There appears to be more questions about people's expectations coming from an ICE environment and being thrown in to an EV option thinking that everything will be the same. At least with an ICE car, you know it will be cold to start with and once the temperature sensor goes out I(Honda Jazz) you will get heat and the temperature gauge will reflect what you need. I would also be interested to learn about the direction of air flow with all the dashboard, screen and footwell settings. Starting from work (with no charging facility) on a cold winter evening, I would expect to have the front screen, overtaking mirror and rear screen defrost buttons pressed and a lot of warm air ultimately being blown out or elements heated to clear everything up for safer driving. It still leaves the question about winter driving and impact on range - It is wet, and you need the wipers on. It is cold and you need the heater on. It is frosty and you need the rear screen heater and overtaking mirrors elements on. What range then? Great video and opening up some tantalising questions.

[@EVPuzzle]

Michael, I think you've got it and understand where I'm coming from. There's too much not knowing and it's hard to appreciate the car until you've owned it in varying conditions. I did not expect half power or less charging at 5c. Whether that's right or normal is another question . Range seems to be affected less than I expected by having the heating on but cold damp mornings are definitely less efficient than dry days.

[@BSAT10]

You can start the heating on the Leaf from your mobile phone app while you are having your morning coffee and the car will be warm and defrosted before you set foot outside the door

[@michaelkitchen5719]

@@BSAT10 Which is fine while you prepare to go to work. Once at work with no charging facilities, for the return, the whole normal ICE heating regime starts once the 'engine' is started and moving. How does that compare with starting an EV from scratch in the cold?

[@zxyqwerty123]

You noted the heating wasn't very good, do you need the HEAT as well as the A/C buttons on to properly heat the car up? It's not clear in the handbook.

[@markjennings2315]

Andy B best method is auto and set temp and wait. It will always be either ac or heat, never both st same time.

[@leexgx]

@@markjennings2315 can have AC with heat

[@markjennings2315]

@@leexgx No, as you raise the temperature controller knob (In auto) the Blue AC light will go out as the heat orange light will come on. As you can imagine it would not be correct to AC cooling fighting against the Heater.

[@leexgx]

@@markjennings2315 AC is not just for cooling it dehumidifies as well (auto typically turns on the AC by default heat or cold) i would assume most EVs have climate control

[@markjennings2315]

@@leexgx I can only go by what happens on my Kona!

[@volvocars5189]

Have you turned off the ADS (auto defogging system)? I think that is the root to the cold air blowing sometimes even when the temperature is set "high". At least it helps on the IONIQ BEV.

[@EVPuzzle]

I always have Auto off..

[@AB-yt4hd]

Yes, I was also wondering at first with my Ioniq why it was so difficult to heat the car. Until I found that we have to disable the ADS.

[@steeveeleevee6484]

Hello Nigel, Another reviewer is suggesting that the Kona needs to be all wheel drive as the review I have seen shows that in the wet wheelspin is also impossible to eradicate unless you accelerate very gently, what has your experience found please?

[@EVPuzzle]

If that's EVM , I did note he was in sport mode , full power, foot to the floor in poor road conditions. Not exactly sensible or representative but definitely illustrates the point with EVs having instantly available torque and the Kona having lots of it, you have to respect it just like you would a 300hp rwd car in the wet. A winter drive mode, more effective traction control , would have been useful but ECO mode surfices and makes get aways easier.

[@dojohansen123]

It really would be better if you refrained from trying to just "figure out" why you observe what you observe. When you say it seems to you there's some kind of significant issue, you may very well leave a lot of viewers believing that there is in fact an issue - when neither you nor they know that there is. Charging is fairly complicated stuff, and there are always many factors influencing the rate. Just to illustrate, consider the fast charger for a second. It has a simplistic nominal rating for it's maximum power, but an engineer would look at maximum current and voltage separately. Why? Because you charge a battery by applying a voltage to it's terminals that is slightly higher than the open-circuit voltage of the battery, but with polarity reversed, causing current to flow in the reverse direction (as compared to discharging). Current flows according to Ohm's law, U = RI, and the *net* voltage at the battery terminals is basically just the sum of the contributions from the battery pack itself and the charger. So if the pack is at 350V and you apply -352V, you effectively have -2V forcing a current through the battery. It is crucial to realize that R, the internal resistance of the battery, is quite low, and the charging voltage therefore only a little higher than the pack voltage. The consequence is that you're not free to simply jack the charger up to maximum voltage. In this example, if you charge at 354 V instead of 352 V, you *double* the charging current. So, in practice, chargers are current-limited. Voltage is only relevant in that it needs to go high enough to allow charging - a few volts higher than the target voltage that you want to charge to. Some "50 kW" chargers can deliver maximum 100A and 500V, some can deliver 125A and 400V. The latter are in practice 25% faster (assuming the car can fully utilize it) because 400V is sufficient to charge any EV on the market to 100%. A popular configuration in EV battery packs uses 96 cells in series, for a nominal voltage of about 3.65V*96 = 350V. Depending on SoC, the pack will be at about 300V to 400V, and a 100A charger therefore cannot deliver more than 30 kW at the low end, while a 125A one could deliver 300V * 125A = 37.5 kW. That's just considering the charger, and I'm sure what I've mentioned is a huge simplification glossing over many caveats and ignoring several relevant issues. What speed you actually get, and ought to get, is a much more complicated question than just what the charger is able to deliver. Making decisions about that - what charging speed the car would *like* to get - is just one of the responsibilities of the BMS - the battery management system. It isn't a fan, and you can't hear if it is running at not. It should be running at all times, and nothing in this video indicates it doesn't. In fact, the fan itself would not normally be considered a part of the BMS, but merely connected to it. It is really better to think of it as a piece of software that makes decisions for the purpose of managing the battery, although in some context it makes sense to think of it as a circuit board (say, if you are an amateur car maker who wants to use the BMS from an Ioniq in your project). The point isn't to try to teach you the engineering. Nor could I, and not just because of the limitations of KZbin comments. I only have amateur-level knowledge of some bits and pieces of the relevant engineering. But I know enough to realize how much I don't know, and enough to tell you know significantly less than I do. So I am trying to offer constructive criticism here. Refraining from guessing the technical explanations doesn't mean you shouldn't test "the technical stuff". Lots of people may not know even the fact that you don't always get the same charging speed, and a test like this makes them aware of the fact. It also makes it clear that it is not as simple as charging speed being a function of SoC, even on the same charger. (My guess, btw, is that you received less power initially on the first charging session because the battery pack was cool. But it's just a guess.) I am personally interested in the technical stuff and would kinda like to understand better how it all works and what tradeoffs are made, noting how different manufacturers choose different tradeoffs. But that isn't what your videos are about. You've stated yourself that your approach is to "get in and try it", not to "spend hours doing research". That approach works well enough for judging how the product actually performs - it is pretty much the normal user perspective. But just like you shouldn't really state as a fact that car A has a crisper turn-in than car B thanks to its double-wishbone suspension unless you actually know what you're talking about, I think your videos would really improve if you simply stated that you feel car A has a crisper turn-in than car B. It would also eliminate some cringe moments, like when you say "the BMS came on". It just shows you don't really know what a BMS is. While that doesn't disqualify you in any way from reviewing electric cars, it kinda does disqualify you from making judgements about whether the BMS is buggy or "has issues". :)

[@EVPuzzle]

How about having a go yourself rather than moaning to me. I'm an ordinary guy with a lay man's view which is appreciated by many.

[@pauldunneska]

I'm just giving a like for effort, such a long and detailed text.

[@robertmontgomery7158]

The EV Puzzle He gave you polite feedback. Being defensive is not the best approach.

[@EVPuzzle]

Robert , I just don't enjoy comments telling me what I should or shouldn't do. Technically his details were constructive but telling me what I could or should say in my videos based on my lower level of engineering crossed a line for me. In this instance I actually knew more than he did about how the Hyundai BMS system worked ( Hyundai gave me additional information not available publicly) but I chose not to use all the acronyms and details as it gets too technical and turns too many people off. Yes, I'm sounding defensive now I guess but I don't tell other people what to do as I'm not them. Its hard work producing these videos and impossible to get all my points across perfectly but I choose to do it in a natural unscripted style which many seem to like. If the tone of his message had not been telling me what to do I would have probably thanked him and applauded the comment. Its a fine line. Generally most peoples comments are great and make the channel better but a few just bug me as they're overly critical of what I do. One day I'll learn not to reply but sadly I care.

[@manvin3363]

@@EVPuzzle Thanks for the informative video. its nice to see a customer's perspective. im not sure what the guy above was rambling on about but i appreciate your video. and the reason cold weather limits the charge time is completely due to preserving the battery. Cold batteries need to be handled with a lot more care to avoid permanent damage (especially during charging) and therefore the BMS cuts way back on the current when it sees the battery is in a 'vulnerable' state. definitely an active area of research in batteries but for now the best the manufacturers can do is try to heat up the battery to its sweet spot to charge faster

[@eduardpertinez4767]

One question to investigate: I do like to put the car to sport and Regen Level 1. That makes the car feel much lighter and powerful, and Regen Level 1 makes it feel like an ICE with its natural engine resistance. Now, it would be great if I could use the brake knowing all goes to regen if I am gently enough. But I don't know how the brakes work. Do they use regen to the limit and only then they physically brake? Or it is someway more progressive, acting on both at the same time and therefore loosing some energy in heat? I have not seen anyway indication in the console on when the physical brakes do start to work. I see the regen acting but I never saw anything in the console that tells you: Now I am using the physical brakes. It would be great if we knew something more about it, would'nt it?

[@markwebber4699]

Just to clear a few things up was the 39kwh battery preconditioned in the morning using winter mode? I found this makes a big difference with a cold battery.

[@VesoljeNet]

I am interested about this too. I guess the Winter mode was not enabled during the test drive and charging.

[@EVPuzzle]

Winter mode is completely separate and not relevant in the temperature ranges tested

[@markwebber4699]

@@EVPuzzle i understand winter mode is a separate bit to the car. However winter mode is used to precondition the battery therefore warming it up so its at idea running temp performance to drive and charge. ➃ ‘Battery care’ shows the momentary power and energy consumption which are used when: • Operating the winter mode to increase the battery temperature during winter to improve the driving performance. • Cooling down the battery temperature during summer to prevent over temperature of the battery. hope this helps explain your results.

[@EVPuzzle]

Mark I've had the detailed info on winter mode from Hyundai and their workshop manual. It has no affect above -10c. It avoids the car going into turtle mode at too low temperatures. Winter mode on or off would not have impacted this set of tests, so I've been told by Hyundai

[@glenmason9755]

Nigel, nice set of videos comparing the two versions. The in-car heating issue is getting frustrating and will probably get worse as the temperature drops. I may have to report the Hyundai.

[@EVPuzzle]

Cheers Glen

[@malcolmknight6450]

There have been suggestions on SpeakEV that the Heat button must be pressed as well as the A/C to get things to work properly. Sounds odd to me and I've not used my Kona since reading that so no idea whether it makes a difference.

[@EVPuzzle]

The Kona has smart air intakes to supposedly limit exactly this, limiting the impact of cold air outside. I'd guess it's the calibration of this system needs fine tuning

[@malcolmknight6450]

Just spent 20 minutes in a cold Kona playing with the heating controls. The Heat button comes on automatically with the Auto button but can be used by itself. I had expected warm air to start blowing straight away as there is no water to heat and circulate but there is a significant delay before air starts to blow warm and in the 20 minutes I sat playing the car interior never did get properly warm. 11C outside.

[@jujitsuboy730]

Malcolm Knight That's not normal for an EV. I drove a Fiat 500e for the 2 years I waited for my Tesla Model 3 and can tell you that both cars are blowing hot air within 30 seconds. It's almost funny how fast you can defrost a completely frozen vehicle. I used to worry about cracking the windshield. They might be using a heat pump which is more efficient but less effective at lower temperatures.

[@M0LHA]

Just a few comments. 1# Kona has a heat pump, these are increasingly inefficient the closer you get to zero ambient. 2# I'm not sure about the Jona but the cooling/heating systems are shared in the Tesla. The car takes priority - this could explain why it's cooler 3# I suspect your 64 does/would make a racket but it's quite cold in the UK at the moment - it could be that the car is simply heating up the batteries to increase the charge speed 4# Not all charges are created equally, some may deliver less power than you'd expect 5# Charging speed is quite variable due to SoC, battery temperature, ambient temperature etc.

[@EVPuzzle]

All useful but as Hyundai quote 57mins to 80% we're back into small print territory like the Nissan Leaf.

[@M0LHA]

@@EVPuzzle Hmm, that basically assumes it's charging full chat without any slowdown to fill the 31.2kWh battery (80% of 39kWh). At current charging speeds that's VERY optimistic. It may be more realistic once the 150kW chargers "trickle" out

[@andytomm1]

I think you are mixing the terms here: Battery managment system (B.M.S.)controls the charge current& voltages to each cell (or paralelled thereof) to equalize and protect them. The noise of the fans obviously is to keep the temperature within limits, and not necessarily part of the BMS.

[@EVPuzzle]

Well yes, as we know the EPCU controls the temperature of the coolant really but everyone's more familiar with terms like BMS so it's easier to lump it all together so the majority understand.

[@iainmackie7064]

My car tapers a lot when charging on DC. But there seems to be a correlation between State of Charge (what’s in the battery) and the Charge Rate (in kWs). In the 38kWh Kona it seems to be about 90. So take the SoC away from 90 and it gives you a rough expected Charge Rate. eg if battery is at 70%, Charge should be about 20 kW. (90-70=20). At 40% SoC, Charge Rate should be about 50kW (90-40=50). It’s very wet finger but seems to work, and is an indication if the Chargepoint is not delivering rather than the car not taking enough. Might be worth seeing if there is a similar correlation in your 64 kWh Kona. (NB Doesn’t seem to work at the very bottom 15% or less, or very top of SoC, 85% or above)

[@EVPuzzle]

Ian, doesn't explain 14kw at 50-60%

[@iainmackie7064]

I agree, It doesn’t. Sometimes there can be a bit of stagnation before the charge session settles down (although not normally for 10 minutes), or it could indicate a faulty chargepoint. As I said it’s a pretty wet finger in the air method. It’s not 100% reliable but I find it better than nothing. The other examples in your video seem to match the 90 sum. Often, when I think I’m getting a slow charge, if I do the correlation sum, it turns out the rate is about right. But sometimes the numbers don’t stack up. That’s the time I look to change to a new chargepoint.

[@iainmackie7064]

Having gone over the video again, I missed the bit where you were only getting 14kW @ 50-60%. But your other examples do seem to show a trend (the trend being the BMS tapers the charge which is a good thing, for the battery.) 3:24 53%/38kW (total 91) 3:34 54%/33kW (87) 3:44 69%/21kW (90) 3:49 73%/21kW (94) 3:54 75%/14kW (89) 4:01 80%/14kW (94) Second Charge 8:16 32%/34kW (66) but just started 8:32 64%/25kW (89) Third Charge 10:12 44%/33kW (77) but just starting 10:26 49%/42kW (91) 12:34 69%/22kW (91) 12:55 91%/10kW (101) above 90% 13:00 94%/9kW (103) above 90% From this I conclude the battery tapers according to how much is in it. (My car does very similar). It can be slow at the start of a charge, and you seem to get a minimum charge rate above 90%. If aircon or BMS fan is on, it consumes electricity so my charge changes slightly as not all the electricity coming in is going to the battery; some of it is being used to run stuff. It used to frustrate me that I wasn’t getting the full rate, all the time. I now know not to expect that, so it’s no longer SO frustrating. It would be interesting to know if there was a 'correlation' on your own car with the larger battery. I have to say I find your videos showing how it actually is on a trip, or how you find it, to be so much more useful than just reading the brochure. Really useful info. 👍🏻

[@EVPuzzle]

Cheers Iain. I have the excel data from the three charges but haven't charted it yet. When I do I think it'll make interesting viewing compared to my own 64kwh on the same charges at same time of day etc, as like for like as possible. My gut feeling is the tapering starts earlier in the SOC range plus there's more tapering at the owner end of SOC thus squeezing the middle bit where you get full power for just a few minutes.

[@EVPuzzle]

Iain, I didn't say on video but I went back to the same charger 2hrs later same SOC but I guess warmer battery after driving and got full rate expected. I suspect the cold battery slows you down... A lot

[@EVMYT]

I see you also hilighted my reasons for wanting heated seats in an EV lol. They are essential in the winter in electric cars and a bare minimum expectation on any car over 15k these days.

[@whocares264]

I heard of a man who traded in his long range 64kwh kona for a short range BMW mini ....now that's a puzzle.

[@EVPuzzle]

Smart man, battery isn't the be all

[@Stokkelo]

You should shut the ADFS off in order to keep warm air blowing.....

[@tracyhemphill-hewitt6549]

Hi there, we have been watching your channel, and are now very interested in buying one, but have a question for you. Does the insurance work out much more expensive ? Like yourself we have found that most of the garages in England aren't interested and don't have a car to show you. We did find a local garage in Northern Ireland that knows a lot about the car and actually have one that they use and we are now going for a test drive. The only down side is, if we do order, the expected delivery date is next September. Thanks

[@EVPuzzle]

Tracy, SLM Hyundai Norwich can get you in a Kona. Insurance is just like any other car if you choose an insurance company that's got their act together. Price is just down to insurance group. Internally insurance companies will be concerned accidents might cause damage to the battery hence an expensive repair but reality is they're full of better safety tech do less prone to accidents. I paid only £100 more than for a 1.6diesel ford fiesta. Very reasonable for a car nearly 3 times the value and twice the power. Longer delivery times are inevitable, it's the best out there at the moment

[@tracyhemphill-hewitt6549]

@@EVPuzzle many thanks for info will let you know how test drive goes

[@tracyhemphill-hewitt6549]

hi there again we have been looking at hyundia s web site and have noticed the kona ev price seems to have gone up ??? or is it me

[@stephenclay6852]

I agree with you the IONIQ is a better buy based on your tests. It rapid chargers a lot faster and has no rapid gate issues.so it may not go as far between chargers but quicker to charge makes up the time spent at the charger.

[@EVPuzzle]

Exactly. What I wish Hyundai would answer is... Why is the Kona 39 slower than the older tech Ioniq. The Kona should be a leap forward but in the 39kwh it's actually a step back it seems. They should've put 45kwh or more in it.

[@stephenclay6852]

I agree

[@sicox100]

Nigel. We've got a Tesla and it sounds like a jumbo jet sometimes when the bms cooling fans get going.

[@stevemccormack9948]

Looks like it might operate according to an algorithm, when to charge fast and slow according to temperatures and conditions etc. The longevity is the issue I think. For a lot of people rapid charging is not so much of a problem. But one thing - what is the normal range of the 39KwHr? If its in the order of 170 miles its still a great little car.

[@EVPuzzle]

If you extrapolate from that trip it's sub 160miles in those conditions

[@DopeyDalek]

With the HVAC issue, have you tried adjusting the flow balance and direction of the air yourself? If so, that might explain some of the unbalanced air temperatures. I have an Ioniq and used to have that problem. I now just set the temperature and put system in auto mode. I'm toasty warm and the heat arrives much faster than any ice I've driven.

[@EVPuzzle]

That could be the reason, trying to be clever and doing it without Auto

[@SuperDiagnostic]

That's a great review again Nigel; thank you so much for your efforts. Can I just ask; when you are parked on rapid-charge can you use the cars main heater to warm the cabin? and the same question when you are on a slow charge, i.e. 16A + 32A. Much appreciated my friend.. Happy EVing..

[@EVPuzzle]

Yes to both, all cars features work as per normal

[@David_Parr]

Good video ! I have Renault Zoe 40Khw and the fans will kick in when the battery starts to get too warm in the summer mostly , but in the winter you hardly hear the fans at all. I wonder because you tried to rapid charge after only a few miles and it at this time of year like the Zoe the battery needs to warm up first even if the state of charge is low. Does the Kona have a Battery Temperature display like the Nissan Leaf ? I can use Canze software and a OBD2 Dongle device that is plugged into the OBD2 socket to see the Battery Temperature , the zoe like's to have a warm battery pack above 20c and a low State of Charge ( 20%) to get maximum speed on a Rapid , which from 20% to 80% takes around 60mins (program is called leaf spy on the nissan leaf ) In the summer i think the result would have been different also maybe the cooling / warming on the bigger battery is better. I always charge the car at home the night before in winter otherwise if you charge before the battery is warm the charge speed on a Rapid will be low especially in the winter.

[@EVPuzzle]

No battery temperature display and no odbII devices working yet. Autopi looks good though but the data for the Kona won't be understood yet I guess

[@johnnorth9355]

The throttling may be because of grid issues rather than the car. The UK's infrastructure is creaky (close to collapse if you believe some insiders) and cold days with high daytime grid usage will cause power distribution issues. Best to try this again overnight I'm afraid when grid usage is lower. Clearly not Nissan levels of rapidgate though.

[@EVPuzzle]

John, that presumes a rapid charger monitors grid activity and throttles according. Have you found anything that confirms this. Btw this was early Sunday morning so no peak times at all

[@johnnorth9355]

@@EVPuzzle It's more that the local grid monitors demand according to the supply it is allocated and distributes accordingly. The power generation is taken online/offline according to predicted demand so Sunday morning will see a minimum of backup supply on-line. A cold morning easily eats up surplus and local network throttling can then be implemented to prevent outages. The whole system is very efficiently run but is on a knife edge as older power stations are decommissioned. The downtime and maintenance of the rest has to be factored into supply both locally and nationally as well (grid loss being a function of distance). A very complex testing environment !

[@BSAT10]

@@johnnorth9355 Hi John as someone who worked for Bonar Long ,Hawker Siddeley, and GEC all suppliers of the National Grid I can reassure you that your "insiders" are wrong

[@EVPuzzle]

John, so you're saying the grid throttles businesses electric supply? Either I'm obtuse or I just don't understand what you mean. The charger is a business location. Its provided power at a stable rate. I see no reason for this business to have its supply limited than any other business so its supply should be stable. Chargers use less power than other businesses so it makes no sense to me to think time if day would impact how much power is given out from a rapid charger.

[@marcvanleeuwen5986]

Not the 40kWh Leaf's levels of rapidgate, but worse than that. From what I've been following, nobody ever gets the "promised" 50kW with a Leaf, but people start calling it rapidgate when the power goes down to about half that, and anything below 30kW is considered quite disappointing. Here we have such levels from the very first rapid charge, with occasionally an unexplained much lower rate (and also occasionally an equally unexplained "normal" rate). And that while thermal management should remove most need for such throttling down.

[@glideman]

You failed to take into consideration that the charging stations don't supply a constant charge rate. We have two electric cars in our family & have swapped over the charge from one to the other at charging stations, we found that the station would reduce the charge rate as it got hotter & the fans kick in as the station heats up. We also found some other variables which affect the charge rate. Sometimes the rate would drop for no apparent reason, maybe the charger drawing too much current from the local grid. I wouldn't buy the Kona for another reason, the PLASTICS, bad enough on the inside but on the outside? Makes the car look cheap. Glad you mention when things are interesting and very interesting as it's not always apparent ;-)

[@PaulMansfield]

Maybe you can use that thermometer to measure the battery temperature before, during and after charging?

[@EVPuzzle]

I did on the casing, couldn't access anything else. 7 degrees before rapid charging 12 degrees after. Its obviously well shielded

[@williamcox1176]

Just a thought, Under battery care, did you have winter mode off?

[@EVPuzzle]

Winter mode is separate. Its use is intended for -10c and beyond extreme conditions. Normal UK weather is handled the same with regardless of that setting

[@williamcox1176]

Again that has saved me reading the manual, If your ever in the Stratford upon Avon area pop over and set the whole thing up for me, please.

[@EVPuzzle]

Yeah right lol, I hate ready the manual too. Winter mode isn't really clear from the manual it sounds like it turns the battery heating function on or off but in fact it's about managing the feature where motor power is limited if it's too cold. Winter mode enables you to have more power to drive as the battery is being heated. The trick is to charge you car just in time for when you're leaving do the battery warms a bit before leaving. That's what I tend to do, leaving at 7am so set timers for 5am to 7am only etc. #Jintc just in time charging

[@williamcox1176]

Ok, Went to the local Instavolt (Lovely Experience) 60% 40kw, 68% 34kw, 74% 23kw, 82% 20kw, Not the best test as started at 60% (only had it 2 days) but will let you know the stats when if ever i charge from around 20%. If you have a twitter account let me know as can send photo's.

[@EVPuzzle]

Cheers William, email and Twitter details are in the description of each video. @KonaElectric

[@williamarmstrong7199]

I would expect charging on a cold battery will always be much slower than a warm battery. Power output from a cold battery is also lower. Is there no pre conditioning app that allows you to warm the car up before you go out on cold mornings? That should also heat the battery a bit.

[@pauldavison7105]

Great vid as usual. But could you please include cost of charge at these public charge points. I'm currently considering EV as my next car and cost and availability of charge points I think is key to my needs.

[@EVPuzzle]

Paul, I definitely forgot that. Its not easy including everything. The Instavolts were both on free bend bit would be 35p per kWh dispensed. Obviously with heaters on and battery care on, that would be more than the kWh added to the battery. The Engenie charger at Peterborough was free again but should have been a flat fee of £4

[@pauldavison7105]

@@EVPuzzle thanks for that. I live in an area with less chargers than you probably have so its good to know what to expect when our local infrastructure improves. Keep up the good work. We appreciate it.

[@EVPuzzle]

Paul, yes Norwich has 4 rapid chargers I'm aware of but all central to Norwich itself. There's nothing around the coast or on the major routes in/out.

[@delboy4711]

@@pauldavison7105 If you have off street parking you would do almost all your charging at home, and you would not be interested in local chargers. It is the availabilty of chargers a long way from home on your travel routes that becomes more important. If you have no off street parking and are dependent on public chargers, then membership of the Polar Plus network is the best option which will cost about £10 a month plus 10.5p per kWh used.

[@pauldavison7105]

@@delboy4711 that may be your view and needs , but it's not mine.

[@senna4281]

Hi I have a Hyundai plugin hybrid. It has just had its first service. I have very little mileage using the engine maybe 100 miles or more total mileage was 3400 and the bill for the service came back at £150. When I asked why the had changed the oil and air fillets they said that what is done after twelve months. Do you think this is wrong is the garage cheating the customers by doing this. Should electric cars have a different service pricing knowing they will use the engine less. We keep hearing that electric car should be cheaper to service, well let’s see it. What do you think out there of this. Have any other plugin or full electric cars challenged there pricing on servicing.

[@EVPuzzle]

Plug ins could easily cost more to service having both elements to check and work on??

[@senna4281]

Yes I know this. If you read my question it was if the engine had done very little work should they have changed the filters.

[@EVPuzzle]

Yes if it's on the schedule then yes

[@therandomtester9561]

I earlier wrote that the reported average consumption in the (my) old Leaf is not correct (every time). I reset everything the other day, down to about 50% now, if you extrapolate the shown numbers the car would report something like 13-15kWh usable, while the truth is around 18 kWh I believe. Showing around 15kWh/100km average now, I think it should be much higher, driving in around 0C with heater on these days. Doing the math on your travel here however, it seems alot more spot on. So maby it's only Leaf that can't do this right? 77.7 mi (124km) on 60% extrapolate to 206km on 100%. 17.26 kWh/100km * 2.06= 35.55 kWh That shouldn't be very far off the true usable capacity, right?

[@EVPuzzle]

Usable is 39kwh apparently but I'd agree the GOM is accurate, battery % maybe less. Needs decimal places

[@therandomtester9561]

@@EVPuzzle your right, 39kwh usable, I forgot that Hyundai/Kia does it the right way, not serving lies as most of the other companies :) Add in a little buffer at the low end, heat loss in battery, lacking deciamls and my 35.55 is quickly 10% of, so it's even closer to 39. Anyway, IF the average consumption in the car is fairly correct, the calculated batterycapacity like I've done now should be very close every time ;)

[@EVPuzzle]

Rayner, I think you're right

[@PH03N1X70]

Does the KONA have active cooling and heating of the battery? Is the battery getting too cold I wonder?

[@EVPuzzle]

Exactly, we don't know. Maybe it's management is too effective while driving.

[@johnjackman2743]

Hi Nigel, Interestingly the Cheatsheet comparison on the Online site, ev-database.uk, shows that the 39kWh Kona has a 38% lower Rapid Charging Rate! Regards John (Signpost)

[@0Nick0]

Is the 39kwh liquid-cooled? Why would a liquid-cooled BMS require such a strong fan?

[@EVPuzzle]

It might not be a fan.

[@Macmonkey1000]

The coolant has to enter a radiator at the front to dissipate the heat to the environment, the fan assists this process greatly.

[@tracyhemphill-hewitt6549]

hi there again we have been looking at hyundia s web site and have noticed the kona ev price seems to have gone up ??? or is it me

[@rangerek]

Not sure if I missed it - only 39kW has problems with cabin heating or both?

[@EVPuzzle]

Both had the same issue.

[@rangerek]

Oh crap :( any comments from Hyundai?

[@EVPuzzle]

None yet. To be honest the Press office listened but then did nothing. Too much effort to investigate I'd guess. Haven't given up yet though

[@rangerek]

The EV Puzzle if it lacks heating in cabin that is a major issue requiring guarantee claim :) and a major concern for having a car for €40k

[@EVPuzzle]

Its in to be looked at tomorrow but I suspect it's by design. Potentially the smart part of the system could be diverting heat to the battery. Hopefully I'll find out

[@magnar7150]

Since you received low charging speeds for both Konas and received fast charging on the 39kWh on the third charge. Did you ever doubted the charging infrastructure to be the problem, NOT the Kona itself?

[@EVPuzzle]

Low charging on the 39kwh only. None of those tests were of my 64kwh

[@magnar7150]

@@EVPuzzle I understand, I missed that. However: Didn't you receive 42kW at some state during charge no 3? Just trying to figure out why a 39kWh pack wouldn't accept 48kW as the Ioniq with 28kWh pack will.

[@EVPuzzle]

Exactly, odd. I did see 43kw for a very short period on charge 3 and my data shows a small amount on charge 1, just a lot less of the higher rates than you get with the 64kwh. I'll post the charge rates in a graph when I get chance

[@eb1888.]

If this were my car I'd ask Hyundai to check for a faulty bms. The behavior is too inconsistent. I'd also like to know who the battery manufacturer is. SK Innovations has been mentioned as an additional supplier besides LG.

[@be236]

So , can you do this same test with your 64kWh Kona EV?

[@EVPuzzle]

I will

[@johanjonsson3591]

Could the Fan be unbalanced? Hear with Hyndai if this is the sound in every 39kW Kona , its just not OK and this Model will taken off my shoplist!

[@scottm5425]

Wow that charging seems very low compared to my 30kwh leaf.

The author seems to be a full on newbie in the electric car area and suffers from the "Range anxiety" syndrome. It would be useful to understand that charging depends also on the amperage of the charger and the temperature of the battery pack. Those are the two main ingredients. Charging at 120A (or 85A in cities) would produce a lot of heat, hence the "I have no idea what the management is doing" bit - the battery pack is being cooled. Another tip maybe is that there is no point of charging a cold battery from 5X%, since this is bound to be a really slow charge. Rather leave it overnight at home on 10A. Sorry I do not speak kWh, I only speak A.

[@marcvanleeuwen5986]

Thanks for this instructive video, though I can understand your disappointment. Just a minor remark (since you're using the term so often): when you say Battery Management System, you seem to mean "battery cooling" or what some call Active Thermal (battery) Management. I think the term BMS usually refers to the _electronics_ that controls charging/discharging and is found on just about any Lithium-ion battery nowadays, as a minimum to protect it from conditions that could lead to the batteries exploding. All EV's have an elaborate BMS with which one can communicate via the OBD port.

[@EVPuzzle]

Marc I'm aware technically the BMS is the electronic management part of the system however in plain English all the stuff together is a system which manages the battery. A battery management system. If I was accurate and said "set this via the AVM so that the ECMU can tell the BMS" it's simply techie speak that means nothing to many. I'd rather annoy a few by mis speaking around terms and acronyms. It doesn't mean I don't actually know how it works. You've said this very nicely however so, thank you. Others seem to think it's worth their time teaching "me" like when I say KW when I mean kWh. I do know the difference of course but sometimes that's what comes out and it can't always be editted out.

[@themanofmead5273]

With a 39kw Kona on order...I’m concerned. We need to understand what is going on here. My first thought is it’s most likely to be to do with temperature. Hyundai need to make more information available about the charging and BMS processes.

[@EVPuzzle]

I agree but they've blanked all my questions on this. Its top secret it seems. Its for potential buyers like yourself that I've struggled with this video. I love the car but something feels very different with the 39kwh when charging with no explanation as to why. I have to say what I feel. Yes my view is tainted by the bigger 64kwh that charges faster but in both instances the lack of information about what is going on and why doesn't give confidence unless you close your eyes and trust.

[@unpluggedEV]

Most likely the owner and driver of the vehicle does not need to know anything about the internal BMU processes. You buy it, you drive it, the software takes care of the rest. I know from my own problems with the Outlander PHEV how frustrating this is. We are lucky as we have the PHEV Watchdog app which reads all the info from the car and displays it nicely on the phone. We could resolve a lot of weird behaviours by analysing the data. Huynday may not know either as this is fixed programmed in the BMU algorithm. Only their engineers in Korea will know. But they don't tell anyone ;)

[@EVPuzzle]

I agree, but secrecy doesn't help build confidence in their cars. The not knowing is frustrating over something important. Battery health

[@eduardpertinez4767]

I'd tell you not to worry too much. You'll normally leave home with 100% charge every morning and range enough for the full day. Rapid charging is expensive (at least here in Catalonia) so you try to avoid it anyway.

[@themanofmead5273]

Eduard Pertíñez yes I agree most of the time there isn’t need to be concerned. In my case I’m planning a road trip to Spain from the England that would necessarily require multiple fast charges. This would be within the first month from delivery (June 2019) so this issue would be very important to me very soon after purchase. The other 99% of my driving and ownership would be fine. But it’s a worrying start.

[@EVMYT]

No heated seats and a potential rapid gate issue.

[@EVPuzzle]

Don't say that word... On the subject of conspiracy, I wonder why Norway didn't get the 39kwh 😉😉😉

[@EVMYT]

The EV Puzzle seriously, I like you're honesty about the car. That's rare these days. You have hilighted a very serious issue.

[@EVPuzzle]

The 39kwh felt so much more limiting than my own 64kwh. It's easy to presume they're the same apart from range . It had to be said as people are ordering the car based on my videos it seems so the truth is key. I did give Hyundai a heads up become hand as a courtesy

[@EVPuzzle]

Cheers

[@EVMYT]

The EV Puzzle I totally agree. Lack of heated seats killed 39kwh for me but this kills it dead. I'll be ordering another i3 in March for 2k deposit and £262 plus vat as its a steal compared to kona. Can't believe they want 4500 deposit and 520 per month. That's ludicrous. For the record I didn't want a 2nd i3 but this kona isn't in the game at that price and leaf has rapid gate and is overpriced.

[@brianeduardo1234]

For the anoraks - not very clear - too much time to charge

[@nigelweir3852]

Join the club ,Zoe same mad heating, seems a lottery

[@SuperFredAZ]

You are mixing kw and kwh in your video. kw is the rate of charge or discharge(like flow rate of 15 litres/min), kwh is total energy (like liters of fuel).

[@EVPuzzle]

I can only guess you're new to my channel

[@SuperFredAZ]

@@EVPuzzle if you are going to host a quasi- science channel you should know the difference between power, and energy.

[@EVPuzzle]

If you're going to comment like you know things, you should know the difference between mis speaking and misunderstanding

[@BSAT10]

Hi Nigel With luck this might show a graph of % charged in red and the charging rate at that level in blue For our 40Kw leaf (about 13C) drive.google.com/file/d/1NMmVRT9l8Ai8WHZJ4ou9frhgwkSpKKBO/view?usp=sharing

[@EVPuzzle]

That's linear. Not stepped like the Kona

[@4dmoore]

Awesome stuff! Can you do a charge test your car and the 39 at the same to see if they charge at the same rate on the same charger at the same time? This might show the issue is with the charger and not the car.

[@EVPuzzle]

Sadly no I couldn't drive two cars at once and didn't have a 2nd driver for my car. A repeat with my own car seems sensible

[@MrKeke2502]

You're geting very inconsistant results, I think (or I hope) there's an issue with that car, try to report it to Hyundai and test an other one. The BMS seems faulty

[@EVPuzzle]

It was reported to Hyundai in case it was a concern.

[@uspussussum]

That device does not measure air temperature.

[@EVPuzzle]

Nope it measures the vents temperature

[@Cloxxki]

Much lower charge rate than Ioniq, they may have been using cheaper cells, a lot cheaper!!

[@98dizzard]

If I recall correctly the Kona uses a new chemistry that is cheaper and higher density but less tolerant of heat.

[@enyaq_gorm]

Kona gate?

[@simonstafrace7771]

Hyundai rapid gate

[@EVPuzzle]

Slower charging than expected from cold for sure. 39kwh seems less capable charging but that's not quite a gate...